SM6FHZ 432 MHz Meteor Scatter Planning

Patience and persistence is the mother of 70cm meteor scatter!

As a newbie to 432 MHz meteor scatter I need to have a good scheme to follow when doing my planning for the best utilization of the showers. 

Objective

To find and propose a simple and efficient method for planning Meteor Scatter skeds in order to get as much out of the shower as possible with the knowledge available to us today.

I have implemented the equations for calculating the radiant position versus time of the meteor showers into Matlab and compiled it into a standalone application that can be used without access to Matlab. I call it RadiantCalc and it is presently in version 2.0. You can see examples of the plots generated by RadiantCalc below. Many thanks to Dr. Peter Duffett-Smith of University of Cambridge for the great assistance in understanding how to implement the equations for calculation of Sidereal Time as well as for calculating the shower peak time from the known Solar Longitude into RadiantCalc.

Meteor showers

So far I have implemented Quadrantides, Lyrids, eta-Aquariids, Perseides, Draconids, Orionids, Leonids and Geminids in the tool. There is also an "Other" option where you can give the RA, Declination and Solar Longitude for the shower you would like to do calculations for.

Planning

There are a few parameters that are good to grasp when planning for meteor scatter skeds on 432 MHz. 

1. Calculation of the predicted time for the peak of the shower for the year in question is done in RadiantCalc. The input information in RadiantCalc is taken from the Meteor Calendar found at the IMO web page. Here is a link to the Meteor Calender for 2019 (pdf-file). Use the solar longitude (lambda index Sun) under "Maximum" from the table at the end of the list. This value for Solar Longitude for 2019 is implemented in RadiantCalc as the default value. This value is used in RadiantCalc for calculating the predicted time for the shower maximum. This value is approximate and may not exactly reflect the radio maximum. If information on the radio peak is available from previous years this may be used to get a better prediction by adding about 6 hours from last years radio peak. You need to adjust back for years with a leap day.
   
     
   
   
2. Use the above retrieved data when running RadiantCalc.
   
   
   Enter the shower you want to calculate data for (Note; case sensitive) by typing the proposed short for it into the dialouge box and click on "OK" or simply click on "OK" if you want the default.
   
   
   In this box you can change shower parameters that does not fit your calculation, i.e. Solar Longitude, declination or RA of the shower if you disagree on the default values. I.E. if you feel you have better information about Solar Longitude than the data in the IMO table, you can use that data for the calculation. Write a "Y" or a "y" in the next box for plotting a line in the plot showing the calculated best directions for the time you write in the lowest dialouge box.  Click "OK" when you are ready to proceed. 
   
   
   Enter the year you would like to calculate and change month or day if you disagree with the default values for the shower in question.  If you want to include Daylight Saving Time, enter the number of hours applicable. Enter your Time Zone. Enter UTC if you would like the plot to be presented in UTC rather than in your local time. Note; "UTC" and "local" is case sensitive. Click "OK" when you are ready to proceed.
   
   
   Enter your latitude and longitude, if you do not want to use my latitude and longitude that is the default value. Click on "OK" when you are done in order to perform the calculation.
   
   
   You should now see something like this, but with your entered data.
   
   
   
   You now get a question if you would like to do more calculations. The default value is "Y" for yes, type "N" or "n" if you want to quit. Click "OK" to proceed. The new plot will be a new figure number with the new data, keeping the previous plot intact. Cut the plot using the "Snipping Tool" if you like to save it for later reference. You need to exit RadiantCalc before you can use the Windows Snipping Tool.
   
   

You can follow this procedure and use this tool for planning your 432 MHz Meteor Scatter skeds and work.

Examples of radiant graphs from RadiantCalc below.

 Radiant position plot as function of UTC for Geminids at 57.64 deg N

  Radiant position plot for Quadrantids at 57.64 deg N

Version 2.0 GUI

Revision history

Version 2.0:

• New GUI
• Call sign and direction line of target station in plotting implemented

Version 1.53:

• Cosmetic errors corrected in handling erroneous data input and data input headlines

Version 1.52:

• Code for detecting and handling erroneous data input introduced for Date/Time and Longitude/Latitude in addition to other already present erroneous input detection

Version 1.51:

• Cosmetic improvements in plotting

 Version 1.5:

• Best directions line plotting at a prescribed time introduced as an option
• Multiple plots handling
• Larger figure plot size
• Latitude and longitude presentation in plot show 1/100 of a degree
  

Resources

The International Meteor Organization web page: https://www.imo.net/

Meteor Calendar from IMO: https://www.imo.net/resources/calendar/

More info on meteor scatter: https://www.rudius.net/oz2m/ms.htm 

OK1TEH info on meteor scatter: http://ok1teh.nagano.cz/ms_70cmlog_text.htm

Updated Februay 16, 2021.              http://www.2ingandlin.se/SM6FHZ.htm